ABSTRACT
Thomas Aquinas's Understanding of Real Distinction of Esse and Essentia — focusing on comparison with Giles of Rome
This thesis takes as its point of departure a question that has been largely presupposed rather than examined: whether the ...
ABSTRACT
Thomas Aquinas's Understanding of Real Distinction of Esse and Essentia — focusing on comparison with Giles of Rome
This thesis takes as its point of departure a question that has been largely presupposed rather than examined: whether the formula ‘real distinction(distinctio realis)’, so widely accepted as the foundational starting point for inquiry into Thomas Aquinas's metaphysics, is in fact Thomas's own. That Thomas discusses a distinction between essence(essentia) and existence(esse) is beyond dispute, and the expression ‘real distinction’ has accordingly been deployed, almost as a matter of course, in nearly every treatment of Thomistic metaphysics. Yet this expression was not used by Thomas himself in any systematic way to characterize the essence-existence relation. Rather, it was Giles of Rome who, after Thomas's death, explicitly introduced and foregrounded this terminology in the course of constructing his own metaphysical system. This paper aims to establish this textual fact and to demonstrate that, beneath the shared label of ‘real distinction’, Thomas and Giles in fact presuppose fundamentally different metaphysical structures.
To this end, the thesis first surveys how expressions such as distinctio/compositio realis, secundum rem, and realiter actually function across Thomas's corpus. This survey reveals that the bulk of such usage occurs in Trinitarian contexts, where these terms serve as theological tools for clarifying the opposition of relations among the divine persons, and that Thomas notably refrains from explicitly applying this terminology when addressing the ontological structure of creatures. The thesis then turns to an analysis of Thomas's argumentation concerning creaturely diversity, creation, and the relation between essence and existence. For Thomas, essence is not an independently pre-existing recipient standing prior to existence, but rather the internal determination of existence that is brought about together with existence within the divine creative act itself. The distinction is real not because two independent principles are juxtaposed side by side, but because this non-identity constitutes an objective, intrinsic ontological structure within the creature. Giles, by contrast, argues in his Super De Causis commentary that creaturely diversity originates from differences among the natures that receive existence, a framework in which essentia is presupposed as logically prior to, and as the locus for the reception of, exsitence. Further, in his Super librum I Sententiarum and in the Theoremata de esse et essentia, Giles characterizes essence and existence as two things (duae res), arguing that essence stands in potency with respect to existence, while existence is a distinct principle that enters from outside the essence to confer actuality upon it. This Giles's conception of ‘real distinction’, as an extrinsic distinction between two independent principles, diverges fundamentally from Thomas's own understanding.
The foregoing discussion thus brings into focus two points that warrant particular caution in the interpretation of the expression ‘real distinction’. First, although this expression appears to capture the very core of Thomistic metaphysics, it in fact carries the risk of refracting Thomas's thought through an Giles's framework. Second, Thomas's understanding of existence and essence is not merely the product of metaphysical analysis taken in isolation, but is inseparably bound up with the Christian doctrine of creation. Where these two points are overlooked, use of the expression ‘real distinction’ risks distorting Thomas's original meaning.
Keywords: real distinction, Thomas Aquinas, Giles of Rome, essence, existence, creation